diff --git a/keyserver/src/services/blob.js b/keyserver/src/services/blob.js
--- a/keyserver/src/services/blob.js
+++ b/keyserver/src/services/blob.js
@@ -107,8 +107,11 @@
   const headers = await createRequestHeaders();
   const blobResult = await downloadBlob(hash, headers);
 
-  if (blobResult.result !== 'success') {
+  if (blobResult.result === 'error') {
     return { found: false, status: blobResult.status };
+  } else if (blobResult.result === 'invalid_csat') {
+    await clearIdentityInfo();
+    return { found: false, status: 401 };
   }
   const blob = await blobResult.response.blob();
   return { found: true, blob };
diff --git a/lib/components/base-auto-join-community-handler.react.js b/lib/components/base-auto-join-community-handler.react.js
--- a/lib/components/base-auto-join-community-handler.react.js
+++ b/lib/components/base-auto-join-community-handler.react.js
@@ -5,6 +5,7 @@
 import * as React from 'react';
 
 import { NeynarClientContext } from './neynar-client-provider.react.js';
+import { useInvalidCSATLogOut } from '../actions/user-actions.js';
 import { useIsLoggedInToIdentityAndAuthoritativeKeyserver } from '../hooks/account-hooks.js';
 import { extractKeyserverIDFromID } from '../keyserver-conn/keyserver-call-utils.js';
 import {
@@ -80,6 +81,8 @@
   const prevCanQueryRef = React.useRef<?boolean>();
   const canQuery = loggedIn && !!fid;
 
+  const invalidTokenLogOut = useInvalidCSATLogOut();
+
   React.useEffect(() => {
     if (canQuery === prevCanQueryRef.current) {
       return;
@@ -127,6 +130,9 @@
           const blobHash = farcasterChannelTagBlobHash(channelID);
           const blobResult = await downloadBlob(blobHash, headers);
           if (blobResult.result !== 'success') {
+            if (blobResult.result === 'invalid_csat') {
+              void invalidTokenLogOut();
+            }
             return null;
           }
 
@@ -180,6 +186,7 @@
     getAuthMetadata,
     keyserverInfos,
     canQuery,
+    invalidTokenLogOut,
   ]);
 
   const potentiallyIncrementBatch: (
diff --git a/lib/shared/invite-links.js b/lib/shared/invite-links.js
--- a/lib/shared/invite-links.js
+++ b/lib/shared/invite-links.js
@@ -22,8 +22,10 @@
     : {};
 
   const blobResult = await downloadBlob(inviteLinkBlobHash(secret), headers);
-  if (blobResult.result !== 'success') {
+  if (blobResult.result === 'error') {
     return null;
+  } else if (blobResult.result === 'invalid_csat') {
+    throw new Error('invalid_csat');
   }
 
   const resultText = await blobResult.response.text();
diff --git a/lib/utils/blob-service.js b/lib/utils/blob-service.js
--- a/lib/utils/blob-service.js
+++ b/lib/utils/blob-service.js
@@ -87,6 +87,7 @@
 
 export type BlobDownloadResult =
   | { +result: 'success', response: Response }
+  | { +result: 'invalid_csat' }
   | { +result: 'error', +status: number, +statusText: string };
 
 async function downloadBlob(
@@ -100,7 +101,9 @@
     headers,
   });
 
-  if (response.status !== 200) {
+  if (httpResponseIsInvalidCSAT(response)) {
+    return { result: 'invalid_csat' };
+  } else if (response.status !== 200) {
     const { status, statusText } = response;
     return { result: 'error', status, statusText };
   }
diff --git a/native/navigation/deep-links-context-provider.react.js b/native/navigation/deep-links-context-provider.react.js
--- a/native/navigation/deep-links-context-provider.react.js
+++ b/native/navigation/deep-links-context-provider.react.js
@@ -10,6 +10,7 @@
   useVerifyInviteLink,
   verifyInviteLinkActionTypes,
 } from 'lib/actions/link-actions.js';
+import { useInvalidCSATLogOut } from 'lib/actions/user-actions.js';
 import {
   parseInstallReferrerFromInviteLinkURL,
   parseDataFromDeepLink,
@@ -20,6 +21,7 @@
 import { getKeyserverOverrideForAnInviteLink } from 'lib/shared/invite-links.js';
 import type { KeyserverOverride } from 'lib/shared/invite-links.js';
 import type { SetState } from 'lib/types/hook-types.js';
+import { getMessageForException } from 'lib/utils/errors.js';
 import { useDispatchActionPromise } from 'lib/utils/redux-promise-utils.js';
 import { usingCommServicesAccessToken } from 'lib/utils/services-utils.js';
 
@@ -92,6 +94,7 @@
   invariant(identityContext, 'Identity context should be set');
   const { getAuthMetadata } = identityContext;
 
+  const invalidTokenLogOut = useInvalidCSATLogOut();
   const loggedIn = useSelector(isLoggedIn);
   const dispatchActionPromise = useDispatchActionPromise();
   const validateLink = useVerifyInviteLink(keyserverOverride);
@@ -125,6 +128,10 @@
             await getKeyserverOverrideForAnInviteLink(secret, authMetadata);
           setKeyserverOverride(newKeyserverOverride);
         } catch (e) {
+          if (getMessageForException(e) === 'invalid_csat') {
+            void invalidTokenLogOut();
+            return;
+          }
           console.log('Error while downloading an invite link blob', e);
           navigation.navigate<'InviteLinkModal'>({
             name: InviteLinkModalRouteName,
@@ -140,7 +147,7 @@
         navigation.navigate(SecondaryDeviceQRCodeScannerRouteName);
       }
     })();
-  }, [currentLink, getAuthMetadata, loggedIn, navigation]);
+  }, [currentLink, getAuthMetadata, loggedIn, navigation, invalidTokenLogOut]);
 
   React.useEffect(() => {
     const secret = inviteLinkSecret.current;
diff --git a/web/invite-links/invite-link-handler.react.js b/web/invite-links/invite-link-handler.react.js
--- a/web/invite-links/invite-link-handler.react.js
+++ b/web/invite-links/invite-link-handler.react.js
@@ -7,6 +7,7 @@
   useVerifyInviteLink,
   verifyInviteLinkActionTypes,
 } from 'lib/actions/link-actions.js';
+import { useInvalidCSATLogOut } from 'lib/actions/user-actions.js';
 import { useModalContext } from 'lib/components/modal-provider.react.js';
 import { threadInfoSelector } from 'lib/selectors/thread-selectors.js';
 import { isLoggedIn } from 'lib/selectors/user-selectors.js';
@@ -15,6 +16,7 @@
   getKeyserverOverrideForAnInviteLink,
   type KeyserverOverride,
 } from 'lib/shared/invite-links.js';
+import { getMessageForException } from 'lib/utils/errors.js';
 import { useDispatchActionPromise } from 'lib/utils/redux-promise-utils.js';
 import { useDispatch } from 'lib/utils/redux-utils.js';
 import { usingCommServicesAccessToken } from 'lib/utils/services-utils.js';
@@ -34,6 +36,7 @@
   invariant(identityContext, 'Identity context should be set');
   const { getAuthMetadata } = identityContext;
 
+  const invalidTokenLogOut = useInvalidCSATLogOut();
   const dispatchActionPromise = useDispatchActionPromise();
   const dispatch = useDispatch();
   const { pushModal } = useModalContext();
@@ -61,6 +64,10 @@
         );
         setKeyserverOverride(newKeyserverOverride);
       } catch (e) {
+        if (getMessageForException(e) === 'invalid_csat') {
+          void invalidTokenLogOut();
+          return;
+        }
         console.error('Error while downloading an invite link blob', e);
         pushModal(
           <AcceptInviteModal
@@ -72,7 +79,14 @@
         );
       }
     })();
-  }, [dispatch, getAuthMetadata, inviteSecret, loggedIn, pushModal]);
+  }, [
+    dispatch,
+    getAuthMetadata,
+    inviteSecret,
+    loggedIn,
+    pushModal,
+    invalidTokenLogOut,
+  ]);
 
   const validateLink = useVerifyInviteLink(keyserverOverride);
   const threadInfos = useSelector(threadInfoSelector);